Die-cutter.



No. 832,076. I PATENTED 001?.2, 1906. H. w. OSTBR.

DIE CUTTER.

APPLICATION FILED MAY 15, 1905.

minedd cial 71 1. @W gal-W UNITED STATES PATENT OFFICE.

HERMAN W. OSTER, OF CLEVELAND, OHIO, ASSIGNOR TO THE OSTER MANUFACTURING COMPANY, TION or OHIO.

'OF CLEVELAND, OHIO, A CORPORA- DIE-CUTTER.

Specification of Letters Patent.

Patented Oct. 2, 1906.

each die shall be concave to correspond with the curvature of the pi e or rod to be threaded and that the threads siiall taper rapidly away from the pipe at that edge of the die which first encounters the ipe, so that. these threads, called roughing-t eads, may be effective in removing the scale or other unevenness from the pipe. As these roughing-threads,

. however, start the cut, it is necessary that they be formed as an accurate continuation of the main threads. The tool I have provided for making these dies consists of a peculiarlyformed cutter adapted to be rotated on its axis and operate on one or more dies placed radially thereto. The cutter consists of three sectionsfirst, a roughing-section, then 'a main screw-threading section, and then a tapered screw-threading section. The screwthreading part of the cutter is made with spiral or helical threads, and one thread is preferably omitted between the main portion and the ta ered portion. The threading of the. tapered to be a continuation of the helical thread of the cutter. The cutter is clearly shown in the drawings, wherein Figure 1 is a side elevation thereof. Fig. 2 is a longitudinal section; and Figs. 3, 4, and 5 are cross-sections on the correspondinglynumbered lines of Fig. 2, these views being {.aken in the direction of the arrows on such ines.

Referring to the parts by letters, A represents a suitable spindle adapted to be held in a machine of the general character of a milling-machine and rotated. Surrounding this spindle on a reduced portion a thereof is, first, a collar B, and then the screw-threading portion of the cutter O. In front of the screw-threadin cutter C is a cylindrical portion, however, is so placed as portion a of the spindle. These parts are held against independent rotation by suitable keys E and E, which occupy keyways a and a, respectively, in the spindle. The cutters are held in place againstlongitudinal displacement by a nut F, screwing onto the threaded end a. of the spindle. By having the spindle of different diameters, as shown, the cutter and reamer each have a driving fit on the spindle, preventing any looseness in the tool.

The roughing or reaming cutter D is generally cylindrical, but has longitudinal and slightly diagonal teeth 11, as shown. The threading part of the cutter 0 consists, essentially, of a cylindrical screw-threading portion 0 and a tapered screw-threading portion 0, though these portions are preferably made of the same piece of metal. At the forward end of the portion 0 the points of the threads are cut off to bring the cutter gradually to the same outside diameter at this point as the cutter D. This allows the threading operation to follow immediately and as a continuation of the reaming operation. The tapering threads 0 are a continuation of the same helix which makes the threads 0; but between these two portions a thread is omitted at 0 so that there will be no dulling of the thread cut, as might result if the tapered threads ran directly into the cylindrical threads.

My cutter is especially well'adapted for use with a traveling carriage to which dies are clamped on opposite sides of thercutter and at an angle to a lane normal to the axis thereof. When t e dies are so held, the threads cut by the] cylindrical portion 0 of the cutter are such that they present a tapered face when the dies are held in the same plane in the die-stock, the threads cut by the por-v tion 0 presenting a much more pronounced taper. Such a machine, designed to employ the cutter forming the subject-matter of this application, is shown in my application, Serial No. 255,884, filed A ril 17, 1905, though the cutter is not limite to usewiththat particular machine.

I claim 1. A cutter comprising a cylindrical screwthreadingportion and a tapered screw-threading portion having its smaller end adjacent to the cylindrical portion, both of said portions being formed on a continuous helix and one reamer D, whic surrounds a further reduced 1 thread being omitted at the junction.

2. In a cutter, the combination of a spindle the threader, and a nut screw-threaded on the 10 having a reduced portion, a collar fitted on end of the spindle and bearing against said said reduced portion and bearing against the reamer. shoulder thus provided, a threader having I In testimony whereof I hereunto affix my spiral cutting-teeth and fitted on said reduced signature in the presence of two witnesses. portion against said collar, a further reduced HERMAN W. OSTER. portion of the spindle which the threader l Witnesses: slightly overhangs, a reamer fitted on such ALBERT H. BATES, last-mentioned portion'and abutting against W. L. MGGARRELL. 

